Presbycusis, sociocusis and nosocusis

Data and idealized curves are presented for a number of surveys on the threshold of hearing of persons who were not exposed, by and large, to intense workplace noise. From these results, and on the basis of certain assumptions, new generalized functions are presented to show pure presbycusis (aging) and sociocusis (non-work-noise-induced hearing loss); typical presbycusis; typical sociocusis; and typical presbycusis-plus-sociocusis. Hearing level surveys, conducted in industrialized societies to reveal presbycusis, appear to reflect the joint effects of presbycusis and sociocusis, especially in males, and factory workers may suffer more sociocusis and a greater degree of presumably non-noise-related otological disorders (nosocusis) than are found in the general population.